


Sunshine

by bertererei



Category: Shingeki no Kyojin | Attack on Titan
Genre: Child Neglect, Child Soldiers, Family Fluff, Gen, Mentioned discrimination against Eldians, OOC, Zeke-Eren Age Swap AU, light manga spoilers
Language: English
Status: Completed
Published: 2020-08-02
Updated: 2020-08-01
Packaged: 2021-03-06 07:20:18
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 4,428
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25659610
Author URL: https://archiveofourown.org/users/bertererei/pseuds/bertererei
Summary: Zeke knows how busy his family is. And as a Warrior Candidate, he most definitely should not be childishly demanding attention (being five is no excuse). So he's really glad that his older brother Eren is more than happy to give him the time of day.
Relationships: Eren Yeager & Zeke
Comments: 9
Kudos: 234
Collections: Kisses Bingo





	1. Prompt: Forehead Kiss

**Author's Note:**

> This is for the Kisses and Other Signs of Affection Bingo ([Tumblr](https://bingokisses.tumblr.com/) | [Twitter](https://twitter.com/bingokisses)). The prompts were super adorable and cute that I couldn't stop myself. 
> 
> In case it's not clear, this is in which Eren is 10 years older than Zeke (aka Eren is the older brother). As you've noticed, this is set in Liberio. There are bunch of little things that went into building this universe, but since this is just collection of fluff, let's just get to spoiling Zeke and hand wave everything else away~
> 
> Warning: Zeke-Eren Age Swap AU. Light Manga Spoilers. Family fluff. Child soldiers. Child neglect. Mentioned discrimination against Eldians. OOC.
> 
> Happy birthday, Zeke.

According to his older brother, when Zeke was born, the sun loved him so dearly that she came down to Liberio for a short visit and kissed his hair.

"That's why your hair is golden," Eren said, lovingly running his fingers through Zeke's hair. "Because you are a child loved by the sun."

It's Zeke's most favorite story in the world to hear before bed. And one night, because he doesn't want the story to end and because he wants to feel a bit spoiled, he asks his brother for more.

"Then why is your hair dark brown?" Zeke says.

For a second, Zeke becomes painfully aware of the tired bags under Eren's eyes. That's right. Didn't he aid in a long surgery today? Zeke shouldn't have done that. He should've let Eren go and get some rest. That was horribly cruel and childish of him.

But Eren doesn't chide him. He doesn't scold Zeke for asking such a ridiculous thing. He doesn't roll his eyes and crankily tell him to go to sleep.

Instead, Eren glances around to make sure that no one else is nearby and leans in, motioning that he's about to tell a secret. It makes Zeke a thousand times excited to know that his brother trusts him this much.

"Because I'm loved by the wood fairies."

"I-is that why you're so good with herbal medicine?" Zeke asks, giddy to know the truth.

Eren nods proudly. "That's right. You're so smart! But you have to keep this a secret. The faes are jealous creatures. If they know I've been saying this, they'll take their love away. So promise you won't tell?"

"I promise!" Zeke says solemnly.

With a soft smile, Eren kisses Zeke's forehead. "Sleep well, Sunshine."

*

Sometimes Zeke catches Eren muttering lightly to the plants in the clinic. When Eren realizes that Zeke is staring, he winks and presses his finger to his lips.

Eren hasn't forgotten that he trusted Zeke with such an important secret.

It makes Zeke prouder than putting on the Warrior Candidate armband in the morning.


	2. Prompt: Sleepy cuddles

**Notes for the Chapter:**

> The book Eren is reading is _Lessons from the Historical Medical Delusions_ by Worthington Hooker.

"Grandpa? Is Eren not here today?" Zeke asks, hoping that he isn't disturbing his grandpa too much.

His grandpa glances up from the patient he was talking to with a kind smile. He makes a small motion at Zeke that he'll be right with him. Then he finishes his talk with his patient before returning his attention to Zeke.

"Eren is here, Zeke. I sent him to the back because he looked dead on his feet. I keep telling him that he won't be allowed to take the medical test until he turns 18, but you know how your brother gets."

Zeke finds himself deflating. If Eren is sleeping, then he shouldn't disturb his brother. He knows that, he really does. But he was looking forward to telling Eren all about his day. Not because anything special happened, but because he just wanted an excuse to talk to his brother. With the whole test to become a doctor thing going on, Eren's free time has all but disappeared.

"But knowing him, he's probably studying back there... Honestly, what will I do with him? You tell him no, and he becomes so stubbornly set on that one thing. Zeke, won't you do me a favor and check in on him? If he isn't sleeping, give him a firm lecture for me, won't you?"

It's clear that his grandpa only said that to appease him, much to his embarrassment. He is a Warrior Candidate. He might be five, but he is a soldier fighting for the good of all Marley. Reiner said it was important that no one forgot that.

"You can leave it to me!"

Still, it's nice of his grandpa to watch out for Zeke.

*

It is exactly as his grandpa guessed. Eren is sitting on the couch back here, reading while muttering darkly under his breath. He doesn't seem to have noticed Zeke come in.

"Aren't you tired?" he asks.

Eren startles, which makes Zeke feel guilty. But his brother grins at him to let him know that it's fine.

"I'm too anxious to be tired, to be honest," Eren admits with a sheepish smile. "I feel like no matter how much I cram, I won't be able to pass this test."

Zeke wisely doesn't mention that Eren probably won't be allowed to take this test for a while longer.

"Grandpa said to give you a lecture if you're not resting," Zeke says.

Unsurprisingly, Eren makes a face. "What if we skip over that part and we er... Oh! Why don't you read me to me until I fall asleep?"

Typically, it's Eren who tells Zeke a bedtime story before bed. The thought that Zeke will be the one to do so makes him a lot more excited than he thought he would be.

"Do I have to read?" Zeke asks.

Because the only book in the vicinity looks to be the one that Eren has in his hands. In other words, a book about medical terminology that Zeke is certain he won't be able to pronounce correctly.

"If you want, you can tell me a story instead," Eren offers. He puts the book down and pats the spot next to him on the couch. "Tell me what you did today. Did Reiner say anything funny? Did Porco make fun of himself again? And did you guys ever figure out where the pretty rock in Annie's lunch came from?"

Eren remembered.

Despite how much information he's trying so hard to cram into his head for the medical test, he remembered the mundane things that Zeke told him about his days.

His chest feels warm. For just a second, he's scared that he might burst into tears. But he's a Warrior Candidate. He isn't supposed to cry. So he distracts himself by sitting down on the couch and picking up Eren's book.

"I-I can read this to you, too. I'm really good at reading."

Eren pulls Zeke onto his lap so that he can rest his chin on Zeke's head. "Will you? That would help me so much. You're the best, Sunshine!"

Zeke opens the book to the first chapter and clears his throat. "The lessons which are taught by the h-history of past... d-del... delusions are slowly learned by the medical profession, and still more slowly by the c-comm... community at large..."

*

It's not that the book is boring. Of course not! A book that Eren picked out cannot be boring. It's just that Zeke isn't too interested in the topic, and there are a lot of really big words that he keeps stumbling over. Not to mention he suddenly realized just how tired he feels. He thinks maybe that's why Eren was trying to read this book earlier. It has a spell on it that makes people want to fall asleep.

He lets out a loud yawn but holds tightly to the book so that it doesn't fall. Then slowly, he turns towards his brother to see if Eren really wants to continue this and...

Oh.

He accomplished his mission.

Eren has leaned back against the couch so that his head is tipped back awkwardly. That was probably his way of not putting his weight on Zeke when he fell asleep. Zeke could have handled that, by the way. His brother treats him too gently.

Zeke puts the book down on the nearby table. Then he goes to move Eren so that he can sleep more comfortably on the couch. Eren stirs at the movement and sleepily looks at Zeke.

"It's cold."

"O-oh! I'll get you a blank-"

His brother pulls him back onto the couch and snuggles in.

"We're going to fall!" Zeke protests.

Eren mumbles something that Zeke can't really make out other than the word "warm." Looks like his brother's too tired. Jeesh, and he couldn't fall asleep earlier when he was clearly this tired? Their grandpa is right. What will they do with him?

"Good thing I'm here for you," Zeke giggles.

He snuggles into his brother's warmth.

Just for a little bit, it should be fine to stay here.


	3. Prompt: A kiss on the knee

Maybe it's because Zeke's family runs a clinic, but he never thought of it as a big deal whenever someone skinned their knees. You don't even need a band aid for something like that. You can just spit on it and walk it off.

But he gets the feeling that those kinds of words will not be appreciated.

"You're going to die! You're going to die!" Porco yells, shaking Marcel's shoulders.

Marcel groans. "I'm fine! Porco, shut up. You're so embarrassing..."

"But you're bleeding!"

It really isn't that big of a deal. There's barely any blood. But here these two are anyways at the clinic, making a show. Don't they know how serious of injuries and illnesses that are treated here? But they just have to redirect the resources for dire patients for their little show, don't they?

No, Zeke isn't bitter because when Reiner twisted his ankle, Porco said to walk it off. Zeke isn't that petty of a person. He just thinks that his brother's time can be spent on more important things like Zeke.

"This is really serious," Eren says with a frown when he comes to look over Marcel's skinned knees.

All of Zeke's thoughts evaporate into guilt and fear. Is Marcel really going to die? B-but this is just a case of skinned knees, isn't it? Zeke feels really bad for thinking the bad thoughts he did. He should find a pretty flower later for Marcel as an apology.

"I-it doesn't even hurt," Marcel stammers. He stares at his knees for a second longer before looking up at Eren. "It can't be anything serious!"

Eren clicks his tongue and wags a finger. "That's wrong, Marcel. It's not a matter of how much pain you're in or how serious you think an injury is. Of course, this doesn't hurt for you. You're a hero and a big brother. But the minute you make your little brother worry like this, it becomes very serious."

Marcel closes his mouth with a clack. He seems to think carefully over Eren's words as he looks back down at his skinned knees. Eren gives him a chance to think and turns to Porco.

"I-is it really that serious?" Porco asks in a hushed whisper.

"It is," Eren tells him grimly. "But lucky for you, I'm a really good doctor."

Zeke wisely doesn't mention that Eren was denied from taking the medical test, just as grandpa said he'll be. Now seems like a very bad time to mention that.

"I'm going to teach you a magic spell in case something like this happens again. I can't promise you that it'll work every time; please don't mistake that. But when it works, you'll know."

A magic spell? That's not fair! Eren never taught something like that to Zeke! How could Eren do this? Zeke is Eren's little brother, even if their moms are different. Why is he teaching a magic spell to complete strangers?! Zeke thought he was special because Eren told him about the faeries. But was that really not big of a deal as Zeke believed?

Eren must have felt Zeke staring at him in disbelief and betrayal from across the room because he glances over and makes a small motion for Zeke to watch carefully. S-so this is something Eren wanted to teach Zeke and these two happened to be here, right? That's what's going on? Even if that's the case, Zeke still doesn't feel very satisfied. It's bad enough that these two stole the precious time Zeke has with his brother, but do they really have to learn about Eren's magic as well?

"First, we take care of the wound like we would any other wound," Eren tells Porco and Marcel.

Zeke doesn't like it, but he moves to see the demonstration better. The first step is definitely things that Zeke already knows and can do if push comes to a shove. Clean the wound, apply ointments, and then wrap it up. To be honest, Zeke doesn't think Marcel even needs this kind of attention, especially not for skinned knees. But a review is a review, and those are useful or whatever.

"Then you say the magic spell... 'Pain, pain, fly away!'"

Then Eren leans down and presses a kiss on Marcel's knee.

"Tada! And the magic has been cast." Eren nudges Porco and motions at Marcel's other bandaged knee. "Will you do the honors?"

This isn't a magic spell. It's just the typical embarrassing thing that Eren always does whenever Zeke gets a small cut or is injured in some way. He feels awfully cheated. But in the same breath, he feels glad that this is all the Galliard brothers will be getting from Eren. Eren's true secret of being blessed by the faeries is something only Zeke knows.

"I-I will!" Porco takes a deep breath as if gathering the courage to do something as simple as kiss his brother's knee.

Zeke thinks it's all stupid, but his mood is starting to improve, so he lets it be.

Porco kisses Marcel's knee and then looks up to his brother. Marcel's cheeks are flushed with embarrassment.

"Does it still hurt?" Porco asks.

For a second, Marcel looks annoyed enough to say that he doesn't care. But Eren must have given him a look because Marcel forces himself to take a deep breath.

"It doesn't hurt," Marcel manages out.

Porco beams and turns to Eren with a grin. "It worked! It worked! I know magic now!"

Try that on a sprained ankle. See where that gets you. Not that Zeke is bitter or anything.

Eren laughs and squeezes Porco's shoulder.

"You were amazing. Just don't forget that this spell sometimes won't work. That's why it's important that you make sure you guys aren't getting hurt in the first place. Porco, it's your job to watch over Marcel and protect him, okay?"

Porco nods, looking excited. "I will!"

"I don't need to be protected!" Marcel complains. "I'm the big brother so-"

"Marcel, you're already a master at protecting Porco. Your job now is taking better care of yourself. No matter how protected Porco is physically, that won't mean anything if you hurt him emotionally by getting hurt. Can you please promise me that you'll watch out for yourself as well?"

Marcel closes his mouth and seems to think about it for a bit. Then slowly, he nods, looking dissatisfied.

But watching this exchange, Zeke feels like he learned something.

*

"Do you get hurt, too?" Zeke asks. "Emotionally, I mean, when I'm hurt."

Eren stares at Zeke for a second before smiling softly. He picks Zeke up in his arms and lifts him high in the air. Normally, Zeke loves it when Eren does that. But this feels too much like Eren is purposefully dodging the question.

"Do you?" Zeke asks again.

Eren presses a small kiss on Zeke's temple and holds Zeke close.

"Yeah."

That's all he says, but there's something about the soft way he speaks that makes it hard for Zeke to ask for more information. Not in that he feels like he'll step on a landmine if he asks. But more like... Like he might see his brother fall apart if he pushes. Like this is something that he shouldn't approach.

He drops the topic.

*

A soft hiss of a curse draws Zeke out of his room in the middle of the night. He peeks out into the hallway, where Eren is by the wall, muttering darkly under his breath.

"Eren?" Zeke calls.

"Did I wake you? Sorry! I just... banged my knee against the wall. Feel free to go back to your room."

Eren must have been half-asleep to do that. He's normally not so uncoordinated.

Zeke walks up to his big brother, a small grin on his face.

"Eren, sit down."

"You want me to...? Er... Sure?"

Despite sounding uncertain, Eren does as asked. He sits with his back against the wall and his legs out. Zeke takes the knee that he assumes is the one that Eren banged, since that one was what Eren was cradling earlier, and presses a light kiss on it.

"Pain, pain, fly away!"

He thought that it would make Eren laugh. That Eren would ruffle his hair and call him "Sunshine" affectionately like he always does. But when Zeke glances at his brother's face, he sees the flash of what he thinks might have been tears before Eren covers his eyes.

"E-Eren...?"

His brother wraps his arms around him, pulling him close. Zeke can feel the soft tremors of Eren's body.

"Thank you," comes the soft whisper.

Zeke's mouth is too dry to be able to form something comprehensive. Even if he could, he isn't sure what he would say.


	4. Prompt: Forehead bump

The only time an Eldian is allowed out of the interment zone is with the permission of a Marleyan. An Eldian can spend all of their life praying for such permission, but it's very rarely given out to anyone who doesn't have connections. At least, it used to be.

Since the Young Warriors Program was put into place, those permissions are easier to get for family members of Warrior Candidates.

"So this is what an airship looks up close," Eren whispers in awe. Then excitedly to Zeke, he says, "And you get to ride in one!"

Zeke doesn't think it's that big of a deal, but Eren's excitement is catching. He finds himself sheepishly giggling. 

The rest of their family was supposed to come to send Zeke off on his latest mission, but various circumstances suddenly popped up. Eren was the one who didn't want to go the most at first (Eren always has an aversion to leaving the interment zone. Zeke isn't too sure why). But when he realized that no one else could go, Eren took a deep breath and promised to see Zeke off. To be honest, Zeke couldn't have asked for anyone better to be the last person he sees before he goes on this mission.

"Jaeger," Commander Magath calls, his voice sharp.

Zeke turns to salute and finds that Eren has done the same. His brother's posture is stiff, as one would expect from a civilian. But it is much better than what Zeke feared Eren might try. Zeke wonders if he should let his brother know that he doesn't have to salute like that. Only soldiers are expected to salute. But it's pretty cute of his brother to do it anyways.

"Commander," Eren greets. "It's been a while."

It's something that Zeke has heard in passing. That Eren used to be a Warrior Candidate. Zeke doesn't know all the detail since no one ever talks about it. But those stories must have been true. When the Young Warriors Program was first put into place, Eren was one of the many children who was a part of it. Zeke wonders how and why Eren left the division.

"You look well." Magath hesitates as if there's something else that he wants to say. Then he must have changed his mind, because he motions at Zeke to get going. "Everyone's gathered over there."

"Commander, will you give us a minute to say goodbye?" Eren asks.

To be so bold as to request something from a Marleyan... Zeke gulps lightly. Is that a sign of how familiar they are? Amazing. His brother is way too cool to be able to talk to a Marleyan like that. 

Magath doesn't even glance at them. He takes two steps away from them and holds his position. Zeke thinks that's supposed to be the start of their timer.

Eren kneels down so that they're at eye-level.

"You be careful, okay?" he says. He glances at Magath's back, possibly judging something. Then loudly so that Magath will hear, too, Eren says, "If you ever have to decide between your life and the mission, always put yourself first. A mission objective can be re-evaluated with a different team. But if you lose your life, that's it. Come back home safely, okay?"

Zeke peeks over towards where Magath is standing. Aside from the stiffening of his back, the commander shows no sign of having overheard. There's a story here that Zeke cannot afford to ask about right now. But as soon as he returns, he is going to demand Eren tell him.

"I'll do my best," Zeke promises.

Eren smiles. He gently taps his forehead against Zeke's.

"You're a smart kid. I know you'll be alright. Come home soon. I'll be waiting."

Zeke giggles. "I'll see you soon!"

He waves Eren goodbye one last time before boarding the airship. Eren's form looks sad, waving to Zeke from the land.

Zeke hopes that he can return home fast.


	5. Prompt: Back of head kiss!

When he wakes up in the morning, it's to his mom running her fingers through his hair and gently telling him, "Good morning. Happy birthday."

When he gets down to the kitchen, it's to his dad's bright, "Happy birthday, Zeke! We made you pancakes!"

"I made pancakes. You burned them," Dina corrects him.

Zeke glances around the kitchen and notices that his brother isn't here yet.

"Is Eren...?"

Grisha lets out a heavy sigh. "He said he wanted to get a head start on studying for the test again. I keep telling him that they won't let him take the test until he turns 18. But he just won't listen."

And Eren couldn't have stopped to wish Zeke happy birthday before that?

As soon as the question enters his mind, Zeke feels guilty. He knows that his brother is really determined to become a doctor. It's just the beginning of the day anyways. He'll see Eren later. And if not, he can always track his brother down at the clinic. There's still a lot of time left. He doesn't have to hurry.

"We've prepared a lot so that you can grow stronger," Grisha tells Zeke. "You've done well to get this far, but our goals haven't been met yet. Keep your focus and push through. You'll be fine, since you're my son."

What began as light birthday greetings quickly turns to the usual lecture about the horrible atrocities caused by the Marleys and the importance of this mission, of Zeke's role. 

Zeke can't wait to leave the house.

*

"Oh, it's your birthday, too?" Reiner asks.

"Too?" Zeke echoes.

Reiner nods. "It's also my birthday."

Statistically speaking, that makes sense. There's a limited number of days in a year, but way too many people. You will doubtlessly meet someone who shares your birthday with you. But that doesn't mean Zeke wants to share his special day. It's nothing personal. He just wants today to be for him.

It's such a selfish mindset to have. Reiner is a good guy, and really, it's just a day. Just because they share today doesn't even mean anything. It doesn't make his birthday any less, and it doesn't make Reiner's birthday any less.

It's just a day.

"Happy birthday, Reiner," Zeke manages out.

Reiner's smile looks uncertain as Zeke feels. "Happy birthday to you, too."

The two don't bring up this topic again.

*

When he arrives at the clinic after finishing his training, his grandma greets him with a warm hug and a loud, "Happy birthday!"

His grandpa ruffles his hair and excitedly wishes him, "Happy birthday," too.

The only person missing is Eren. When he asks, both his grandparents sigh heavily.

"He went on and on about that test of his!" his grandma says.

"I keep telling him there's no way it'll be open for him this year either." His grandpa shakes his head.

Then they both add, "You know how he gets."

Zeke gets it. He really does. This test is very important to his brother. But isn't Zeke also important to Eren? It's not fair.

"I want to talk to him," Zeke decides. "It doesn't have to be for long. I won't distract him too much. Please tell me where he is."

Both his grandparents falter, which is the first sign that something isn't quite right. But Zeke's mood is too foul to be able to focus on that right now.

"Please tell me," he demands embarrassingly like a brat.

*

"Eren!" Zeke calls as he opens the door into the study in the back of the clinic.

"Wait! Wait! I'm not rea-"

Too late.

Zeke sees everything.

There's a half-hung banner that Eren is struggling with. Zeke thinks he can make out the word "Happy" on it. The room has been cleaned out so that there's a table in the middle of the room with various food and a giant cake. It must have costed not only a fortune to get this much food, but also to get a cake that big. There also seems to be two presents neatly placed in the corner over there.

Was Eren planning on throwing a surprise party for him? That's why he was so elusive?

"Grandma! Grandpa! You said you would distract him!" Eren exclaims. He sighs. "There goes the surprise..."

"Well, Eren, maybe if you wished your brother happy birthday earlier, he wouldn't have felt the need to barge in like this," their grandpa points out.

Eren blinks. "I didn't wish you happy birthday?"

Zeke suddenly feels relieved. It wasn't that his brother forgot. It's not that his brother didn't want to see him. His brother just had a lot on his mind. Rather, his brother had Zeke on his mind that he forgot to look at the real Zeke in front of him. 

"I'm so sorry, Zeke! I can't believe I forgot something so basic! Ahhhh!" Eren pulls Zeke into a hug. "I'm the worst! Zeke, will you please forgive me?"

"You haven't said it yet," Zeke reminds him.

Eren presses a kiss against Zeke's hair. "Happy birthday, Sunshine."

"I don't know. It doesn't feel very sincere," Zeke says, knowing that's much more childish than he normally would be. It's his birthday, though. It's okay, just for today, right?

"Not sincere enough...?"

Eren thinks about that for a second longer before he grins. He presses another kiss on the top of Zeke's head. Then towards the back. Then all over Zeke's head, until he finally stops with a kiss to the forehead.

"Happy birthday, Zeke," Eren tells him with a soft smile. "Thank you for being my sunshine."

Zeke decides he can forgive his brother just this once.


End file.
